It is known that when paratroopers strike the ground with their inordinate weight due to equipment that they carry, large forces are applied to the ankle with a large number of ankle injuries caused by excessive inversion or eversion of the ankle. Such ankle injury rate is significant and of major concern.
In the process of developing a brace that could be worn in a combat boot and provide ankle protection during a parachute landing, a device was used such as disclosed in U.S. Pat. No. 4,280,489. However, in a recent trial with several hundred paratroopers, it became clear that the bulk of the device located within the boot was more than the average paratrooper would accept unless he had a history of ankle injuries. An effort was made to apply such a device on the outside of a boot to provide protection during the jump and provide quick removal on the ground for disposal with the chute. However, the device disclosed in U.S. Pat. No. 4,280,489, when applied to the outside of the boot, provided little inversion resistance. The two sides of the device shifted on the boot and buckled from lack of support from the shoe.
The present invention overcomes the disadvantages of the prior art and includes lateral and medial plastic supports that are of similar shape and contour to those disclosed in U.S. Pat. No. 4,280,489 which is incorporated herein by reference in its entirety. However, to fix the relationship of the lateral and medial plastic supports to each other and to the boot during the stress of inversion, the plastic side supports are connected by a U-shaped member that wraps around and conforms to the back of the boot. The open end of the U is secured to the boot by a strap that engages the front edge of the heel. In addition, one or more straps on the upper portion of the lateral and medial plastic supports secure the supports in a close relationship to the upper portion of the boot and leg.
The connecting member ideally is made from the same material and molded simultaneously with the lateral and medial plastic side supports. For comfort, the sides of the lateral and medial supports are cushioned with any well-known means such as foam liners or air cells.
Instead of having a U-shaped member integrally formed with the lateral and medial plastic supports that wraps around and conforms to the back of the boot, the U-shaped member may be separate from the lateral and medial side supports and could be adjustably connected for extreme variation in boot size.
Thus it is an important object of the present invention to provide an orthopedic apparatus for use in connection with the outside of a boot to limit the inversion and eversion of the foot while permitting plantarflexion and dorsiflexion thereof.
It is another important object of the present invention to provide a pair of spaced apart side walls for mounting on the outside of the boot and extending longitudinally upwardly to encompass the ankle and lower extremity of the leg above the ankle to enable the ankle to resist inversion and eversion forces. To stabilize the spaced apart side walls with respect to each other, a substantially U-shaped member connects the spaced apart side walls for extending substantially around and conforming to the back of the boot to hold the side walls in fixed relationship to each other and to the boot.
Another important aspect of the present invention is to provide straps that lock the distal end of the brace under the sole at the front of the heel of the boot.
Another important aspect of the present invention is to utilize a cushion between the lateral and medial supports and the boot and leg. The cushion could be a foam liner or an air cell which conforms to the shape of the lateral and medial upright supports.